Don’t stop reading. This isn’t some philosophical piece about what we can learn about life from your cat. Heavens, it’s almost the end of the year and I’m all out of deep and meaningful. It is literally about what your cat sees and why cat’s vision is different to humans.
I often get asked if cats see colour. Let’s be honest, no-one definitively knows the answer to this but the consensus seems to be yes although not to the same extent as humans can. Both human eyes and cat eyes use the retina to send electrical impulses to the brain which then interprets the images we (and puss-cat) see. Within the retina are photoreceptors and within them are rods and cones. Rods allow for night vision and peripheral vision along with shades of grey and brightness. Cones on the other hand allow us to perceive colour and see in the day time. It’s on this aspect that the structure of human and cat eyes diverge. Your Favourite Feline has more rods than cones which is why your cat sees better at night than you. You however have a greater concentration of cones than rods which means you can see a huge variety of colour and that’s quite handy for seeing during the day. Vision however is not only about distinguishing colour but visual field, clarity, and the ability to see at night.
How A Cat Sees
- Visual field: This is basically the extent of your peripheral vision and is a measurement of the total area in which you can see objects when focused on a central point. If you’ve ever gone to the optometrist and been tested for glaucoma (which you should do especially if you have a family history of it) they check your visual fields. The average visual field for humans is around 180°, and the smart people who research animal things estimate that a cat’s field is slightly wider at about 200°
- Clarity: The technical term is Visual Acuity and when people talk about having 20/20 vision this is what they are referring to. If someone says they have 20/20 vision it means that they can see the same line of letters that someone with normal vision can see at 20 feet. Once again, the smart animal research people consider cats to have between 20/100 and 20/200 vision. They need to be much closer to things to see them the same way we do, and anything in the distance is quite blurry. Hmmm, that sounds like me actually.
- Colour: Humans, and many mammals including cats, are considered to be trichromats meaning that we have three kinds of cones that allows us to see the three primary colours. It appears though that cats might have difficulty with reds similar to the way someone who is colour-blind might confuse blue and purple. However, if you’re a cat hunting a mouse or a lizard your tracking them through their scent and movement, not by their colour
- Night Vision: The cats have got it all over us on this one. With their abundance of rods cats eyes are super sensitive to dim light. In fact it’s estimated that cats can see the same as what a human can at night but only require 1/6th the light. That’s a handy skill to have when you’re out on the prowl. There is another structure in the eye called the tapetum which is considered to help with night vision. It seems to reflect light between the rods and cones to the photoreceptors. It’s this that causes the scary Chucky Eyes your cat gets when you see them at night….or under the bed.
So should you consider the colour of toys you give to your Favourite Feline? Not really. Feel free to get stuff in colours that appeal to you. Focus more on the size, shape and weight of the toys which replicate prey that cats would want to hunt in a wild environment. I think it’s these aspects that make our Fur Balls, Mice and Caterpillars so popular with our discerning cat customers. They are light-weight, small and eminently carry-able and hit-able.
There’s a really good article written on this topic which also contains some fantastic images that illustrate how cats and humans see the same image. Check it out here.